Modified influenza virus for monitoring and improving vaccine efficiency

Abstract

The immunogenicity of the influenza virus hemagglutinin (HA) molecule may be increased by substitutions of amino acids in the HA sequence. The substitution of specific HA residues, such as asparagine at position 223 of H5 HA, increase the sensitivity of the hemagglutinin inhibition (HI) assay by altering receptor specificity and/or antibody-antigen binding. HA molecules containing such substitutions will be useful in the development of diagnostic reference viruses and improved influenza vaccines.

What is claimed is: 
     
       1. An immunogenic composition comprising
 (a) a recombinant influenza virus H5 hemagglutinin (HA) molecule, wherein said recombinant H5 HA molecule:
 (i) comprises one or more amino acid sequence changes as compared to a naturally occurring HA molecule that comprises an amino acid other than asparagine at an amino acid position corresponding to amino acid position 223 in H5 HA; 
 (ii) comprises an asparagine at an amino acid position corresponding to amino acid position 223 in H5 HA; 
 (iii) has an increased reactivity with antisera derived from an animal exposed to an H5 influenza virus or an H5 influenza vaccine as compared to said naturally occurring HA molecule; and 
 (iv) is not A/HK/213/03 HA molecule, and 
 
 (b) a carrier. 
 
     
     
       2. The immunogenic composition of  claim 1 , wherein the carrier comprises an adjuvant. 
     
     
       3. The immunogenic composition of  claim 1 , wherein the immunogenic composition further comprises an immunostimulatory molecule. 
     
     
       4. The immunogenic composition of  claim 1 , wherein the immunogenic composition further comprises microcapsules and/or an immunopotentiating membranous carrier. 
     
     
       5. The immunogenic composition of  claim 1 , wherein the immunogenic composition further comprises red blood cells (rbc), rbc ghosts, or blue tongue antigen. 
     
     
       6. The immunogenic composition of  claim 1 , wherein the immunogenic composition is administrable intramuscularly. 
     
     
       7. The immunogenic composition of  claim 1 , wherein the immunogenic composition is administrable orally. 
     
     
       8. The immunogenic composition of  claim 1 , wherein the immunogenic composition is administrable mucosally. 
     
     
       9. The immunogenic composition of  claim 1 , wherein the one or more amino acid sequence changes alter a glycosylation site. 
     
     
       10. The immunogenic composition of  claim 1 , wherein said naturally occurring HA molecule is from a human influenza A virus. 
     
     
       11. The immunogenic composition of  claim 10 , wherein the human influenza A virus is a member of the H5 subtype. 
     
     
       12. The immunogenic composition of  claim 1 , wherein said naturally occurring HA molecule is from an avian influenza virus. 
     
     
       13. The immunogenic composition of  claim 1 , wherein the asparagine at amino acid position 223 of the HA molecule alters specificity for sialic acid receptors. 
     
     
       14. The immunogenic composition of  claim 1 , wherein the HA molecule is part of a recombinant or attenuated virus. 
     
     
       15. An immunogenic composition comprising
 (a) a recombinant influenza virus comprising a recombinant influenza virus H5 hemagglutinin (HA) molecule, wherein said recombinant H5 HA molecule:
 (i) comprises one or more amino acid sequence changes as compared to a naturally occurring HA molecule that comprises an amino acid other than asparagine at an amino acid position corresponding to amino acid position 223 in H5 HA; 
 (ii) comprises an asparagine at an amino acid position corresponding to amino acid position 223 in H5 HA; 
 (iii) has an increased reactivity with antisera derived from an animal exposed to an H5 influenza virus or an H5 influenza vaccine as compared to said naturally occurring HA molecule; and 
 (iv) is not A/HK/213/03 HA molecule, and 
 
 (b) a carrier. 
 
     
     
       16. The immunogenic composition of  claim 15 , wherein the one or more amino acid sequence changes alter a glycosylation site. 
     
     
       17. The immunogenic composition of  claim 15 , wherein said naturally occurring HA molecule is from a human influenza A virus. 
     
     
       18. The immunogenic composition of  claim 17 , wherein the human influenza A virus is a member of the H5 subtype. 
     
     
       19. The immunogenic composition of  claim 15 , wherein said naturally occurring HA molecule is from an avian influenza virus. 
     
     
       20. The immunogenic composition of  claim 15 , wherein the asparagine at amino acid position 223 of the HA molecule alters specificity for sialic acid receptors.